The invention relates to automatically or semi-automatically attaching a canvas or the like onto a framework.
A canvas used in painting, for example, is obtained by fastening, such as nailing or stapling, the edges of the surface of the canvas onto the edges of a framework. This operation is typically carried out manually, and requires much time, it is difficult to obtain an even tension over the entire canvas, and bubbles or folds are formed which bother the painter. The placing of a canvas onto a framework is generally done by an artisan trained for several years in the practice.
The present invention remedies this inconvenience and permits the mounting of a canvas onto a framework by a person not so qualified, utilizing a machine which replaces manual functions automatically.
In accordance with the present invention, the machine is characterized by a laterally movable support for holding the framework and moving it below a nailing or stapling head, along with a means for holding the canvas and ensuring the proper tension of the canvas before it is affixed to the framework.
A feature of the invention is a means holding the canvas in an inwardly curved clamp which is mounted on the shaft of a jack. Other features include a pneumatic or hydraulic piston/cylinder mechanism for actuating the canvas clamping means.
Thus the stapling or nailing is carried out precisely at the desired point or placement, and the canvas at this point is stretched over the framework. The command for these operations takes place through the use of a foot pedal control mechanism which frees use of the hands.
Other characteristics and advantages of the invention will be apparent from the following detailed description of representative embodiments of the invention, with regard to the following figures: